Pretreatment primers which are used in the industrial and automotive industries traditionally are very high in volatile organic content (VOC). Typical VOC levels are upwards of 5.0 lbs/gallon (packaged) and 6.0 lbs/gallon (reduced to sprayable viscosity). Many recent developments in environmental laws and regulations severely limit the VOC content of paint and coating products. For example, the California South Coast Air Quality Management District has proposed VOC restrictions for pretreatment primers of 3.5 lbs/gallon.
In light of the severe VOC restrictions now coming into force, our efforts have focused on developing a low VOC, water reducible pretreatment primer composition which will perform comparably to higher VOC pretreatment primer compositions. This invention relates to a film-forming pretreatment primer for use over clean, untreated metal surfaces having a VOC of less than 3.5 lbs/gallon. The coatings of this invention are particularly useful as pretreatment primers to serve as tiecoats between metal substrates and topcoats in the industrial and automotive industries.